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than one physical port to reside on the same subnet. It could also be used when a VLAN spans multiple
physical networks, or when additional segmentation or security is required.
7.1.1.1.
When to Configure VLAN Routing
VLAN routing is required when the switch is used as a layer 3 device. VLAN routing must be configured to
allow the switch to forward IP traffic between subnets and allow hosts in different networks to
communicate.
In Figure 24 the QNOS switch is configured as an L3 device and performs the routing functions for hosts
connected to the L2 switches. For Host A to communicate with Host B, no routing is necessary. These hosts are
in the same VLAN. However, for Host A in VLAN 10 to communicate with Host C in VLAN 20, the switch must
perform inter-VLAN routing.
Figure 7-1: Inter-VLAN Routing
7.1.2.
IP Routing Configuration Example
In this example, the switches are L3 switches with VLAN routing interfaces. VLAN routing is configured on
Switch A and Switch B. This allows the host in VLAN 10 to communicate with the server in VLAN 30. A static
route to the VLAN 30 subnet is configured on Switch A. Additionally, a default route is configured on Switch
A so that all traffic with an unknown destination is sent to the backbone router through port 24, which is a
member of VLAN 50. A default route is configured on Switch B to use Switch A as the default gateway. The
hosts use the IP address of the VLAN routing interface as their default gateway.
This example assumes that all L2 VLAN information, such as VLAN creation and port membership, has been
configured.
Summary of Contents for QuantaMesh QNOS5
Page 1: ...QuantaMesh Ethernet Switch Configuration Guide QNOS5 NOS Platform ...
Page 209: ...209 Table 7 8 IPv6 Neighbor Discovery Settings ...
Page 226: ...226 Table 8 2 L3 Multicast Defaults ...
Page 254: ...254 Appendix A Term and Acronyms Table 9 5 Terms and Acronyms ...